In industrial practice, the decision to accept or reject an inspected item
is usually made on the basis of measurement information. Since this informa
tion is rarely complete, it is not possible in general to be absolutely cer
tain about the value of the measurand. As a consequence, incorrect decision
s may be made. In this paper, formulae for the probabilities of improperly
accepting or rejecting an item are derived. Bayesian statistics provides th
e theoretical framework, and use is made of the Principle of Maximum Entrop
y. Applications to the inspection of workpieces and to the verification of
measuring instruments are considered and examples are given. The convention
al, frequency-based approach is also discussed.